According to World Health Organization (WHO), cancer is a leading cause of death worldwide, accounting for 7.4 million deaths (around 13% of all deaths) in 2004. Monoclonal/recombinant antibodies, which specifically target clinical biomarkers of disease, have increasingly been applied as powerful tools in cancer imaging and therapy, a fact that is highlighted by some nine FDA-approved monoclonal antibodies (MAbs) or their immunoconjugates (as of December 2008) for use in cancer treatment. In this study, five monoclonal antibodies (MAbs) were generated and characterized against carcinoembryonic antigen (CEA), which is widely used clinically as both a blood and tissue tumor marker of epithelial malignancy. Variable domains (VH and VL) of one the stable MAbs with highest affinity were PCR-amplified and assembled as single-chain antibody fragment (scFv). Following the cloning and expression of scFv antibody fragments in Escherichia coli, the functional binding and specificity of the recombinant antibody were confirmed by ELISA. To develop a direct in vitro detection of CEA-positive cancer cells, scFv DNA was genetically fused to enhanced green fluorescent protein (EGFP) gene and expressed in bacteria. The chimeric fluorescent protein is able to specifically detect CEA-positive cell lines; no cross-reactivity was observed with a negative control cell line. This strategy will likely allow the establishment of a rapid, single-step detection assay of CEA, which is considered to be one of the best predictors of malignancy among all other tumor markers.

Background and Aim:The living organisms on the earth are under the influence of natural gravity force and if this gravitational force changes, they will be affected by a unique shock. Weightlessness has important effects on cell function by interfering with biochemical pathways and gene expressions. Study of these changes would be of benefit to astronauts and can improve the quality of human life on earth. In simulated microgravity, the expression of some genes and protein levels produced in cultured cells or laboratory animals have been altered. However, very little information is available on the effects of microgravity on gene expression. Raf kinase inhibitory protein (RKIP) is a regulator of kinase activity and a cell balancing agent that can act as a metastatic inhibitor in a variety of solid tumors, including breast cancer. In general, the RKIP expression in progressive tumors is reduced but its increased expression can result in reduced invasive potency of cancer cells without affecting primary tumor growth. Materials and Methods: In this study, changes of RKIP gene expression were investigated in human MCF-7 breast cancer cells after 24 and 72 hours exposure to microgravity conditions using qReal time PCR method. We used t-test for data analysis and graphpad prism 7 project for plotting graphs. Results: The results showed that microgravity changed gene expression of RKIP and led to increased expression levels of the gene after 24 hours exposure to microgravity. Conclusions: By optimizing the duration of microgravity, we can observe significant changes in RKIP gene expression in MCF-7 cell line which can be considered promising for the treatment of cancer .